It is also known that this operation is performed by means of automatic machines comprising several stations where the spindles which receive the lid fitting units are located. Owing to the diversity of the various types of containers with the associated lid, however, it is necessary to provide spindles where the lid fitting unit is specific for each type of lid to be fitted. Such units must therefore be replaced whenever there is a variation in the type of lid being used and with the machine stopped. EP 0,850,872 also discloses a rapid engagement/release device which comprises at least one sleeve which is fixed to the spindle and on which there are coaxially mounted at least one bell which is integral with said sleeve and at least one bush which is partially sealingly inserted inside said bell so as to form a chamber and able to be displaced coaxially with respect to the latter by the thrusting action of resilient means and a fluid under pressure which can be supplied upon actuation to the chamber.
Although performing its function, the known device requires the supply of a fluid under pressure with the consequent need to provide corresponding apparatus for producing said supply and feed means able to convey the fluid inside the spindle, thereby resulting in constructional complications and an increase in the costs and the maintenance operations.